In recent years, a heat transfer system for preparing a print from an image electronically formed in a color video camera has been developed. In one method for preparing such a print, initially an electronic image is subjected to a color separation with a color filter. Next, the respective color-seperated image are converted to electrical signals. Subsequently, these signals are modulated to generate yellow, magenta and cyan electrical signals, and then these signals are transmitted to a thermal printer. In order to obtain a print, a yellow, magenta or cyan dye-providing material is disposed on an image-receiving material face to face. Then, both are interposed between a thermal head and a platen roller and are heated from the backside of the dye-providing material with a line type thermal head. The thermal head includes numerous heating elements, which are heated one by one in response to the yellow, magenta and cyan electrical signals. Subsequently, this procedure is repeated for the other two colors. Thus, a color hard copy corresponding to an original image visible on the display can be obtained.
In another method of thermally obtaining a print using the electrical signals mentioned above, the thermal head can be replaced with a laser. In this system, the dye-providing material contains a substance capable of intensely absorbing a laser ray. The dye-providing material is irradiated with a laser ray and the absorptive substance converts light energy to thermal energy and immediately transfers the energy to the adjacent dyes, whereby the dyes are heated- to a heating migrating temperature with the dyes being transferred to the image-receiving material. This absorptive substance is present under the dye in a layer and/or is mixed with the dye. A laser beam is modulated with the electric signals corresponding to the shape and color of the original image and only the dyes in the area necessary to be thermally transferred in order to reconstruct the colors of original image are heated for thermal transfer. More detailed explanations of the above process are described in British Patent 2,083,726A, in which the absorptive substance disclosed therein for the laser system is carbon.
The problem in using carbon as the absorptive substance lies in the fact that carbon comprises fine particles and that it tends flocculate in the coating. This deteriorates the quality of a transferred image. Further, carbon is transferred to the image-receiving material due to sticking or abrasion, which results in speckles in the image and insufficient color in the color image.